/Engine/Source/Runtime/Core/Public/Templates/SharedPointer.h
Constructs a shared pointer as a shared reference to an existing shared pointer's object. This constructor is needed so that we can implicitly upcast to base classes.
template<typename OtherType, typename> TSharedPtr ( [TSharedPtr](API\Runtime\Core\Templates\TSharedPtr)< OtherType, Mode > const & InSharedPtr )